Characterization of MSC-derived EVs.
(a) Size distribution of resting and primed EVs obtained by NTA. (b) Immunoblot analysis of Giantin, LAMP1, Alix, GRP78, HSP70 and CD9 expression in resting and primed MSCs and purified EVs. This blot is representative of three independent experiments showing the same trends. (c) Representative plots of the immunophenotypic analysis of MSC-derived EVs showing the expression profile of a specific exosome marker (CD63), mesenchymal stromal cell markers (CD73, CD90 and CD105), adhesion molecules (ICAM-1 and VCAM-1) and MHC class I and II (HLA-ABC and HLA-DR, respectively). The histograms display the isotopic controls (dotted curve) and specific markers of resting (filled curve) and primed (black curve) EVs. (d) Graph showing quantitative differences of EV release between resting and primed MSCs. Data represented as mean ± SEM of ratio between number of EVs and number of cells of origin obtained from 33 independent experiments. ***P < 0.001.